Science

Carbon dioxide is a major greenhouse gas that traps heat in the Earth's atmosphere, contributing significantly to global warming. Oxygen and ozone do not have the same effect on global warming, and 'None of these' is incorrect since carbon dioxide is responsible.

The lens in the human eye is a biconvex lens, which converges light rays to focus images on the retina. Biconcave lenses diverge light and are not found in the human body for vision purposes.

The different seasons occur because the Earth revolves around the Sun while its axis is tilted. This tilt causes varying angles of sunlight during the year, leading to seasons. Option B is incorrect because Earth's rotation on its axis causes day and night, not seasons.

Medicines or chemicals used specifically to kill or control unwanted plants (weeds) are called herbicides. Insecticides target insects, and fungicides target fungi, so they are not correct in this context.

The cornea is the transparent front part of the eye that is commonly transplanted in eye donation to restore vision. Other parts like the retina or iris are not typically used in transplantation.

Typhoid is a waterborne disease caused by the bacterium Salmonella typhi, typically spread through contaminated water. Rabies is transmitted through animal bites, and asthma is a respiratory condition, not an infectious disease. Therefore, typhoid is the correct answer.

Memory loss caused by brain injury is medically termed 'Amnesia.' Dyslexia relates to reading difficulties, and Schizophrenia is a mental disorder, so they are incorrect in this context.